A security window should provide a high degree of security but should also be capable of being easily removed or opened for emergency escape by the occupant.
In the specific embodiment of the invention about to be described, a security panel is supported in a window opening for sliding movement from an installed position in which the lower edge of the panel is received in a channel to an upper position in which the panel is withdrawn from the channel and may be removed or opened. The panel is locked in the installed position by means comprising a pair of pins mounted on a track disposed above the panel. The pins extend downward and terminate in opposed relation to the upper edge of the panel to prevent the panel from moving away from its installed position. There are a pair of spaced, relatively deep holes in the upper edge of the panel which are capable of receiving the pins. When the pins are aligned with the holes, the panel may be moved upwardly from the installed position because the pins will enter the holes and not interfere with such movement. When thus moved to the upper position, the panel may be removed or opened.
There are a plurality of relatively shallow holes along the upper edge of the panel which, however, are of insufficient depth to permit the panel to be moved far enough to clear the channel, so that the panel cannot be unlocked when the pins are aligned with the shallow holes. The relatively deep and relatively shallow holes are substantially indistinguishable to the touch at the surface of the upper edge so that it would be practically impossible for an intruder to discover the "right combination", that is, the pair of deep holes with which to align the pins, in order to unlock the panel.
These and other objects of the invention will become more apparent as the description proceeds, especially when considered with the accompanying drawings.